Fixes#35993 - Changes to update_size in commit eb4cc31 made it so
the group dict passed into update_size was not modified. As a result,
the 'replace' call does not see an updated min_size like it previously
did and doesn't pause to wait for any new instances to spin up. Instead,
it moves straight into terminating old instances. Fix is to add batch_size
to min_size when calling wait_for_new_inst.
Fixes#28087 - Make replace_all_instances and replace_instances behave
exactly the same by setting replace_instances = current list of instances
when replace_all_instances used. Root cause of issue was that without lc_check
terminate_batch will terminate all instances passed to it and after updating
the asg size we were querying the asg again for the list of instances - so terminate batch
saw the list including new ones just spun up.
When creating new asg with replace_all_instances: yes and lc_check: false
the instances that are initially created are then subsequently replaced.
This change makes it so replace only occurs if the asg already existed.
Add integration tests for #28087 and #35993.